1. Field of the Invention
The present invention relates to a measurement data processing unit having a plurality of relaying unit to which one or plurality of measuring device can be connected and processing means for collecting and processing measurement data sent from the relaying unit.
2. Description of Related Art
Conventionally, a measuring device which detects measurement value as an electric signal by an optical or electrostatic detecting means is known for measuring a physical amount such as a length of a work.
For such a measuring device, for example, a digital dial gauge is known. The digital dial gauge has a gauge body, a spindle slidably attached to the gauge body and a detecting means including a stationary detecting element mounted to the gauge body and a movable detecting element moving synchronously with the sliding movement of the spindle, and detects a relative movement displacement amount of the two detecting element as an electric signal.
The electric signal detected by the digital dial gauge is not only digitally displayed to a display unit directly connected to the digital gauge but also processed to be displayed and recorded by a measurement data processing unit.
[Measurement data processing unit]
In using the measurement data processing unit, the relaying unit is connected to the digital dial gauge, the measurement data is transmitted to processing means such as a personal computer through the relaying unit, and the measurement data is processed by the processing means. The relaying unit here is for transmitting the electric signal sent from the digital dial gauge after converting to be adapted to the processing means, to which one or two digital gauge is usually connected per one relaying unit. In collecting and processing the measurement data sent from a plurality of digital dial gauge, the measurement data is transmitted through a plurality of the relaying unit connected to the processing means.
According to the measurement data processing unit having the measuring device, the relaying unit and the processing means, less work is necessary even in providing a plurality of measuring device to a work to be measured since measurement process is simultaneously carried out by a single processing means. Therefore, in examining a processing precision of a work, simultaneous plural spot measurement can be conducted employing a plurality of measuring device. Accordingly, a deviation against a standard block can be simultaneously confirmed at a plurality of measurement point, thereby diminishing the burden of examining the work.
However, in connecting the measuring device and the processing means through a plurality of the relaying unit of aforementioned processing unit of the measurement data, following problem occurs since all of the relaying unit have to be individually connected to the processing means.
[Problem of address setting]
In the simultaneous plural spot measurement, the measurement data transmitted from the respective measuring device is collected to the processing means. In this case, to secure memory area corresponding to the respective measuring device, address setting for calibrating the memory area and the measuring device has to be carried out. The address setting is determined by connecting condition of the processing means and the relaying unit, and the measurement data of respective measuring device is allocated to each corresponding memory area determined by which relaying unit should be connected to a plurality of I/O port (input/output port) provided to the processing means.
Accordingly, the address setting inevitably accompanies human works of connecting the processing means and the relaying units. And as the measuring device increases, the address setting becomes complicated.
Furthermore, as the measuring device increases, mistake in connection is likely to occur since the number of connection line between the relaying unit and the calculating unit increases. If such mistake occurs, precise collection and process of the processing means is impossible.
[Problem of expansion]
The number of measurement data capable of collecting and processing by a single processing means, in other words, the number of measuring device capable of being connected to a processing means is determined by the number of I/O port provided to the processing means and the number of measuring device capable of being connected to the relaying unit. Accordingly, if further measuring device is required when all the I/O ports are connected to the relaying units, it is necessary to newly provide an I/O port, resulting in difficulty in expanding aforementioned measurement data processing unit.
[Easy-to-extend series connection and problem therewith]
In measurement data processing unit capable of simultaneous plural spot measurement, a device has been developed to facilitate increasing measuring device, in which respective relaying unit is serially connected to adjacent preceding and succeeding relaying unit, and a relaying unit disposed at an end of the line is connected to the processing means through general communication cable such as RS232C.
The measurement data converted into an electric signal by a measuring device is transmitted from the relaying unit to which the measuring device is connected to the processing means, through precedingly disposed relaying unit and cable to the processing means, and through a communication cable from a relaying unit disposed at the end of the cable.
According to aforementioned processing unit of measuring data, each relaying unit is serially connected with each other, and one of the relaying unit is connected to the processing means. So, a new measuring device can be easily installed by serially connecting another relaying unit to the serially connected relaying units and connecting a measuring device to the new relaying unit, thereby constructing easy-to-expand measurement data processing unit.
However, since not all of the relaying units are connected one-to-one to the processing means in the aforementioned measurement data processing unit, it is difficult to immediately specify troubled part by processing means when a part of relaying unit go wrong or the cable connecting adjacent two relaying unit comes down.
It is an object of the present invention to provide a processing unit capable of automatically conducting address setting in a measurement data processing unit having plurality of relaying unit to which one or plurality of measuring device can be connected and processing means for collecting and processing the measurement data transmitted from the relaying units.
It is another object of the present invention to provide a measurement data processing unit capable of easily installing new measuring device.
It is further object of the present invention to provide a measurement data processing unit having relaying units serially connected through a communication cable which is capable of immediately identifying troubled section if the measurement data processing unit should break down.